Interlocking grating and framing system for trench drains



2 Sheets-Sheet l F lG. 3

vf mq D@ bg@ April 9, 1968 INTERLOCKING GRATING AND FRAMING SYSTEM FOR'FRENCH DRAINS riginal Filed April 17. 1961 INVENTOR. GEORGE J. FLEGELATTORNEYS April 9, 1968 G. J. FLEGEL Re. 26,366

INTERLOCKING GRATING AND FRAMING SYSTEM FOR TRENCH DRAINS 2 Sheets-Sheet2 Original Filed April 17, 1961 INVENTOR.

GEORGE J. FLEGEL W8@ @MA-ff ATTORNEYS United States Patent O 26,366INTERLOCKING GRATlNG AND FRAMING SYSTEM FR TRENCH DRAINS George J.Flegel, Michigan City, Ind., assignor, by mesne assignments, to JOSAMManufacturing Co., Michigan City, Ind., a corporation of DelawareOriginal No. 3,221,616, dated Dec. 7, 1965, Ser. No.

103,310, Apr. 17, 1961. Application for reissue Apr. 7,

1967, Ser. No. 637,019

13 Claims. (Cl. 94-34) Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue specification; matterprinted in italics indicates the additions made by reissue.

ABSTRACT OF THE DISCLOSURE In a poured concrete trench drain, flushfronting elements longitudinally robbeted to receive flush, abutting,metal or plastic trench-covering members upwardly displaying a straightline of abutment, each supported by opposite .ends on tlze rabbetshoulders, including like grate-type members covering the major trencharea and having downwardly spaccaI lateral lugs and lug receivingrecesses cooperatively engaged with recesses and lugs of adjacentmembers and each having on at least one end an integral' projectionengaged in a frame element rabbet side-wall groove; and locking membershaving groove engaged-projections on both ends and lateral recesses,disclosed in two types--a ynarrow ller bar type, and a grate-type with ascrew-secured key plate projecting from a recess at the end opposite anintegral tongue projection location; rectangularand sector-shaped gratemembers being disclosed.

The present invention is concerned generally with trench drain framingand grating; and more particularly with an interlocking system offraming and grating for a drain trench.

Trench drains have been used in environments as diverse as water leveldeck swimming pools, streets, door arcas in buildings where water isused for various operations. For such drains the prior art has longknown the use of metal framing elements anchored in a surrounding matrixsuch as poured concrete or other structure in which the trench is formedand supporting at opposite ends each of a series of grating members incontiguous relation, usually at the level of the adjacent drained area,as a top closure for the drain trench.

The present invention is concerned with the provision of framingelements embedded or anchored generally as known to the prior art in theedges of the drainage trench in combination with grating memberssupported in an interlocking relation of framing elements with respectto grating members and adjacent grating members with each other. Furtherthe present invention provides framing and grating members for adrainage trench especially adapted for use with grating members formedof synthetic plastic whereby the grating members are readily locked inposition to prevent casual removal thereof, for example, by patrons of aswimming pool or the like. Specifically the present invention provides,in straight drainage trench sections, framing elements and grate memberswhich in a given section result in an interlocked engagement of o.series of successive and contiguous grating members with Reissued Apr.9, 1968 "ice cach other and with framing elements supporting the sameendwise, with the grate members being of such identity in general formthat the same basic mold may be used for fabrication.

An object of the present invention is the provision of framing elementsand grating members in a trench drain system adapted to an interlockingrelation of the grating members with each other and with the frameelements preventing casual removal without the use of specific tools.

Another object is the provision of a grating and framing system for adrainage trench particularly adapted for use of molded plastic gratingmembers by inclusion of means for interlocking adjacent grating memberswith each other and with framing elements preventing ready removal ofthe grating members and consequent damage thereto.

Other objects and advantages of the present invention will appear fromthe following description and the drawing wherein:

FIG. 1 is a plan view of a portion of a typical structure of a straighttrench drain embodying the present invention;

FIG. 2 is a detail plan view of a typical grating member;

FIG. 3 is a generally central vertical longitudinal section of a gratetaken as indicated by the lines 3 3 in FIGS. 1 and 2;

FIG. 4 is an enlarged fragmentary vertical sectional view of a lockinggrate taken as indicated iby lines 4 4 in FIG. 1;

FIG. 5 is a vertical section through the system showing the manner ofinsertion of a grate member;

FIG. 6 is a view corresponding to FIG. 4 for a modification of thelocking device and associated grate member; [and] FIG. 7 is a plan viewof curved grate members and framing for a curved portion of the drain,as at a rounder corner between two trenches[.]; and

FIG. 8 is a detail of a filler bar locking member.

FIG. 1 of the drawings shows in plan a straight drainage trencharrangement in a concrete matrix or slab structure 10 for conductingwater from the generally horizontal slab surface level 11 to one or moredrainage outlets 17 (see FIG. 5). Opposed parallel like framing elements13, 14 (see FIGS. l and 4) embedded at the trench edges, that is, in theconcrete at the junction of the top surface area 11 and the verticalwalls of the drainage trench itself, support a series of adjacent grates16, 16a in contiguous relation as top closure elements for the drainagetrench. Where, as shown in FIG. l, the trench is not a closed curve, thegrating members at each end of the series are also supported laterallyby respective frame elements 12, 15 in shape identical with 13 or 14.

The framing elements 12, 13, 14, 15 are formed of identical stock instainless steel, brass, or other material suitable for the environmentof use and preferably which may be extruded to the cross sectionappearing in FIG. 4 for element 13. These are anchored in thesurrounding concrete matrix structure by any of the various suitableexpedients known to the prior art. Each framing has a longitudinalrabbet-like formation disposed inwardly toward the trench, providing ahorizontal longitudinal shoulder 13a, a vertical longitudinal shoulderor surface 13b; and between the horizontal and vertical surfaces 13a.13b, a longitudinal groove 13e (see FIG. 4) with one wall a continuationof the shoulder 13a.

The grates I6 as designated in FIG. l (including the members 16ahereinafter described) are individually supported at opposite ends uponthe continuous longitudinal shoulders of the framing elements 13, 14;and also have with respect to each other on adjacent sides aninterlocking relation as will be described. The grates 16 (also 16a) ashere shown all have a generally identical longitudinally symmetricaloutline form which in top plan view is shown by FIG. 2 and in centrallongitudinal section in FIG. 3.

Except corner elements, where such are to be desired for a drainagetrench continued around a curve or a corner, each grating element 16comprises a generally rectangular body 20 apertured or perforated toprovide drainage openings therethrough. On each side, similarly spacedfrom respective ends each grate 16 is provided with a lateral lug andcorrespondingly shaped notch so located that, with two adjacent gratesreversed in orientation, the grooves and notches can interlock. Althoughthe notches on one grate could be roughly diagonally located to eachother, and so the lugs, here oppositely extending lateral lugs 21,downwardly spaced from the top surface, are located near one end of thebody and near the other end are correspondingly located and shapedopposite notches or grooves 23 on the bottom side of lateral edge anges.Equally well, here adjacent like grate elements oriented into end-to-endinverted relation are adapted to an interlocking engagement of thelateral lugs 21 on one in the notches or grooves 23 of the other. At thegrating end adjacent the notches 23, a transverse tongue or flange 25 isprovided for engagement in a frame groove as 13a with like thickness tolugs 21, all slightly smaller than the height of groove 13a.

The endwise projecting tongues 25 have an endwise tongue-and-grooveinterlocked relation with the groove formations alternately of the frameelements 13, 14. At the ends of the trench in an arrangement accordingto FIG. l, the lateral lug 21 of each end-most grating is received in agroove and is laterally supported in a shoulder of the frame elementsl2, 15 corresponding to the groove 13e and shoulder 13a as shown in FIG.4 for element 13.

Grate structure attaining a similar interlock is hereinafter describedwith respect to FIG. 7 for curved trenches.

The length of the trench between the vertical shoulders of the endframing elements 12, 15 is, of course, substantially equal to a multipleof the body width of the units 16 (and 16a), that is, excluding theprojecting dimension of the lugs 21; while the spacing between verticalshoulders of 13, 14 is slightly greater than the grate body length topermit insertion as later described.

A locking grate element or member 16a is disposed at any positionbetween two elements 16, both of which have a tixed location, forexample, as shown in FIG. 1, in consequence of engagement of oppositeend members in the series with end frame members secured in thesurrounding concrete matrix structure. Such a member 16a is interlockedat both ends, and hence serves either by itself or with others as a key`or keys for the entire drain. It is to be understood that, for example,with a tive to six inch Wide trench and the grating element proportionsof FIG. 2 for plastic units as hereinafter de scribed, a locking gratingis preferably located at about every ten feet of trench length.

A locking unit 16a in general form is identical to that heretoforedescribed and shown in the drawings for grating units 16, lacking,however, the lateral lugs 21. Moreover, centrally located at the endopposite the tongue or ange 25, there are formations in the body toaccom modate a lock device. This device includes a plate 30, threadedlyengaged by a screw 31, received in a correspondingly shaped verticalcentral aperture 32 in the grating. The plate is accommodated in :lbottom notch 33 ofthe grate and engaged endwise in a frame slot such 4as 13e (see FIG. 4). Here the screw 31 is disclosed as a socket head capscrew adapted to manipulation from the top surface by an Allen wrench orthe like.

In a straight trench structure shown in the drawings, the gratingmembers 16 are `filed in from each end of the trench, until a singlespace is left for a locking grate member. Each member is placed, asindicated in FIG. 5 `by endwise insertion of its end tongue 25 at oneend into the receiving groove of a frame member. The member is thendropped to bring its other end into bearing relation on the frameshoulder (as 13C in FIG. 4 or 5) on the opposite frame member, and movedlaterally to bring its lug 21 into engagement with an end frame o1' lug21 and notch 23 on one side into interlocking relation with an alreadypositioned grating member.

Finally at a space remaining for a locking grate, a plate 30 iscentrally located in an appropriate longitudinal groove of a member 13or 14; the locking grate 16a is inserted and lowered directly into placefor interlock of its notches 23 over adjacent lugs; and through anaperture 32, in the end of the locking grating member opposite the endwith tongue 25, a screw 31 is threadedly engaged with the plate 30 andtightened up to lock up the entire assembly.

For convenience in the engaging of the screw 31 with :its respectiveplate, the screw receiving bore and the plate may be modified as shownin FIG. 6, where the locking screw receiving plate 30a is provided withan upward conical boss 30h surrounding its threaded aperture, and acorrespondingly shaped female taper 32a leads into the bottom of thescrew aperture bore 32 of the locking grate. This arangement furthersthe finding of a threaded engagement of the locking screw and plate bythe pilot ing" action of the boss and formations.

Where two trenches meet or intersect in a strictly right angle cornerwhere the end of at least the inside 'framing element of one abuts theinside framing element of the other, the latter inside `framing elementmay have at least locally similar shoulder and groove formations on`both sides; so that the doubly shouldered inside frame of one trenchmay serve as an end frame in which is laterally engaged the last grateof the other trench.

In FIG. 7 there is shown the configuration of structure which may beused at a curved or corner region of a drainage trench. The gratesupporting frame elements,

similar to elements 13, 14 are of course appropriately curved andspaced; while the grates assume generally sectorial outline forms.However, in contrast` to the grates shown for a straight trench wherelateral interlock formations occur at identical location (lugs 21 absentin 16a) at least two distinct sectorial forms are required, which,though similar in general outline, have lips analogous to lips 25, lugsanalogous to lugs 21 and notches analogous to notches 23 alternately atopposed ends of successive sectional elements. Alternatively, the curvegrates could be identical, insofar as lug and notch locations areconcerned, where lugs on opposite sides are diagonally located from eachother, and so the grooves; but then where an adjacent straight trenchworks or tills `from one into another curve, the straight length wouldhave to be selected so that the last straight grate would be properlyoriented.

Further should it be noted that the `grating structure above describedis of particular advantage where the grating elements 16, 16a arefabricated of synthetic plastic materials such as Du Pontslight-stabilized acetal type resin Delrin; or for non-combustibility,and where its degree of water absorption is not detrimental, of Nylon."Delrin has appeared thus far particularly advantageous by virtue of itssurface smoothness in molded forms, adaptability to coloring,non-corrodibility in general use, its lack of appreciable cold ow, andits thus far seeming characteristic of being a substance to which slimeand generally bactcrial growths are non-adherent.

Where the grating members may be rotated end for end in the body p-laneto provide the interlock relation, as in 16 (or 16a) for example, allmay be made from the same basic mold cavity, with inserts used inmolding 16a to tfill mold spaces forming lugs 21. Likewise all memberscould [coud] have a notch 33; or an insert, used to form the same in16a, could be removed in molding 16. The aperture 32 can be drilled; oran insert used in a common mold cavity to form the same. Even where castmetal grates are used, analogous procedures may be used in permanentmold casting, or the known procedures for like results with common basicpatterns for sand molding.

Because of practical diflculties in obtaining exactly a trench of anygiven length with preferably a positive tolerance only in trench length,conveniently locking,1 ller bars are also used in the system [l Such abar member, shown in FIG. 8, has say la inch [in] width, [having]locking projections 25a, such as the one end projection 25 in FIG. I, 2,3 0r 5, at both ends [,I.' a long upwardly convergent slot 26 closeenough to each respective end to permit inward deflection of thecorresponding locking projection 25a; and the bottom recessed at 27, tothe depth of groove 23 of the grate members represented in FIG. [1] 3and FIG. 5, for the entire length between the slots, to accomodatetherebeneath lateral lugs 2] of adjacent grate members. Such bars asneeded each may be snapped into locking relation between two adjacentgrates already in place with the frame grooves 13c engaged by theprojections 25a, as permitted by the deflectability of the latter; eachller bar member, thus end-locked, when overlaying tlze lateral lugs 0j'adjacent grate members locking the adjacent grate members in positionagainst lifting; but even apart from end engagement, sach thin bar orbars being not easily removed, baving a locking member function for theassociated grate members precisely by serving as filler means keepinggrate members from` such displacement along the frame elements as wouldallow any grate member to escape a lug interlock with at least onelaterally adjacent structure.

What is claimed is:

1. In a framing and grating system in a drainage trench: framingelements of like cross section anchored in opposite edges ofthe drainagetrench; a series of grate members closing the top of said trench andeach supported at its opposite ends on upwardly exposed shoulderformations of said elements; adjacent said members having interlockinglateral lug and notch formations providing on each side of a member afirst portion adapted to be overlain by a portion of the adjacent memberand a second portion adapted to overlay another portion of the sameadjacent member, excepting a locking member in said series devoid ofsaid lug formations; each of said elements having a longitudinal rabbetformation providing a respective said shoulder formation and also havinga longitudinal groove parallel to, and laterally opening toward thetrench above, said shoulder; each of said members having solely at oneend an integral [propection] projection engaged in a tongue-and-grooverelation with a said groove of one of said elements; said locking gratemember having at an end opposite its said projection releasable lockingmeans engaged with, and in the said groove of, an adjacent one of saidelements; and means engaging a respecive member laterally at each end ofthe series to prevent movement parallel to the trench away from the nextmember of the series.

2. In a drain trench formed in a concrete slab or the like; trenchframing elements of identical cross section anchored in the edges of thetrench and a series of laterally abutting grating members each supportedat its opposite ends on respective frame elements; each framing elementhaving on the upper side thereof a longitudinal rabbeted formationfacing the trench providing a horizontal longitudinal shouldersupporting an end of a grating member, and also having in said rabbetedformation a longitudinal groove open toward the trench; each gratingmember having solely at one end an integral tongue projection inengagement in a said groove of one of said elements; said gratingmembers each having on adjacent longitudinal edges interlockinglaterally projecting integral lugs and laterally open notch formationsproviding on each side of a member a first portion adapted to beoverlain by a portion of the adjacent member and a second portionadapted to overlay another portion of the same adjacent member,excepting a locking grating member in said series devoid of said lugs;said locking member including at its end opposite said tongue a lockplate engaged in a said groove of a said frame element, and a verticallydisposed lock screw through said locking member threadcdly engaged insaid plate and accessible from the top of said locking member to adriving tool, whereby said locking member is secured at its oppositeends in respective frame elements; and means fixed to the slab engaginga respective member laterally at each end of said series preventingmovement away from the next member of the series.

3. In the locking arrangement as described in claim 2, said plate havingan upwardly projecting locating boss surrounding the threaded aperturethereof; and the bottom of said aperture in said locking grating memberbeing formed to receive said boss.

4. In a framing and grating system in a drain trench: longitudinalframing elements and transverse end framing elements of like crosssection anchored in coplanar relation in edges of the drainage trench; aseries of grating members closing the top of said trench and eachsupported at opposite ends on shoulder formations of longitudinalelements; adjacent said members having interlocking lateral lug andlaterally and downwardly open notch formations excepting a lockingmember in said series devoid of said lug formations; each of saidelements having a longitudinal groove parallel to and laterally opentoward the trench above said shoulder and each of said members havingsolely at one end an integral projection engaged in a tongue-and-grooverelation with a said groove of a said longitudinal element; successivemembers having their said projections engaged alternatingly inlongitudinal elements on opposite sides of the trench; and in saidseries a said locking grate member having at an end opposite saidprojection an underlying projecting locking plate engaged in a saidgroove of an adjacent one ot' said elements and having a lock screwthrough the locking grate member threadedly engaged in said plate.

5. A system as described in claim 4 wherein opposite end members of saidseries have a lateral edge supported on a said shoulder and a laterallug engaged in a said groove of respective trench end framing elements.

6. A system as described in claim 4 including in at least a portionthereof a series of identical grating members of rectangular bodyconfiguration with adjacent members in end-to-end reversed orientation,each grating member having the lugs and notches disposed with a lug andnotch on each lateral edge equi-spaced from respective ends of themember.

7. A grate member for a drainage trench with framing members anchored inthe trench edges as described in claim 1, said notches and lugs being somutually located that the same orientation thereof is retained uponturning the member end for end in its plane.

8. The member as described in claim 7, wherein the notches are locatednear one end of the body and the lugs near the other end.

9. In a framing ana' grating system in a drainage trench: framingelements of like cross section anchored in opposite side edges of thedrainage trench; a series of like grate members spanning the top of saidtrench and each supported at its opposite ends on upwardly exposedshoulder formations of said elements; adjacent said members havinglongitudinal sides with longitudinally continuous vertical upper marginswhereby abutting sides of adjacent grate members display a straight lineof abat- 9 1 0 e/f'mf'nrs and 0f form mpedng ready non-insrlmwnml1.721.464 7/1929 Myers 9J-l3 rwnm'a/ from #ze system. 21159.75?. 5/1939Shaw 94-3 113 2,436,593 2/1948 Moselowitz 943 1.1

References Cited The following references, cited by the Examiner, are ofrecord in the patented le of this patent or the original FOREIGN PATENTS164,630 4/1949 Austria.

650 3/1858 GreatBritain.

1,334,222 3/1920 Butler 20-8 1,384,712 7/1921 Shanley 94 35 JACOB L.NACKENOFF, Primary Examuzer.

